Breast cancer is one of the most common incident cancer and cause of death from cancer in women. It is known that several factors that influence hormonal status (e.g., age at first child birth) or are markers of change in hormonal status (e.g., age at menarche and age at menopause) are associated with the risk of breast cancer. Reproductive factors are known risk factors for breast cancer that probably act early in life. They point toward endogenous estrogens as likely player in the initiation, progression, and promotion of breast cancer. An attempt has been made in this article to review the scientific data published in Indexed journals on the role of reproductive factors in breast cancer.